View Full Version : Focusing the G1
5th of August 2001 (Sun), 22:36
Any tips on using either manual or autofocus effectively on the G1?
I'm new to the camera and, coming from a long history of using rangefinder and SLR cameras, find both the autofocus and manual focus frustrating. The image on the LCD is too small for my 50-year-old eyes to accurately judge focus manually, there is no built-in distance marking as there would be on an SLR lens, and autofocus seems to get confused when it can't clearly isolate the foreground subject from the background.
I've read the botzilla.com description of the problem at http://www.botzilla.com/photo/G1focus.html, but it offers no real workarounds. Yet people do create nicely focused shots. What tricks have you folks found? The focus uncertainty is my main disapointment in working with this camera so far.
8th of August 2001 (Wed), 07:59
Considering some of the raging posts recently at http://www.dpreview.com/forums/forum.asp?forum=1010 about this very subject, don't be surprised if there is not a lot of feedback concerning this subject. It has been explained so many ways with no apparent slowing of complaints that most folks are just tired. That's the bad news.
The good news is you can find many, many helpful tips on the Canon forum regarding focus with the G1. If they could all be pasted in this message it would be quite large, indeed. LOL.
9th of August 2001 (Thu), 23:16
I'll try such a summary. I was not, here, trying to complain, but instead to find guidelines and workarounds.
I perused the focus thread a dpreview. It's amazing to me how much time some people have spent trying to sort this out. My sense from reading the thread (and some experimentation) is that:
- The focusing zone is center-weighted
- The focusing zone narrows to roughly the size of the spot metering box if you select spot metering
- The focusing system, when it can't find a contrasty subject in the center of the frame, defaults to focusing on a more distant object, regardless of the contrast level of the more distant object
- Putting a contrasty object, such as a business card, on something non-contrasty that you are trying to focus on improves the odds it will be in focus
- Using the digital zoom makes it a bit easier to see if something is in focus
- Most consumer and prosumer digital cameras have similar focusing limitations
That's about all I could glean from scanning dozens of messages. Anybody able to add to this synopsis?
10th of August 2001 (Fri), 07:58
You got about all I did from that discussion, although the replies keep adding up. I learned a lot from this topic even though at this point it is still in the hypothesis stage from the experimentors involved.
I didn't mean to imply you were going to start a fight, just trying to guess why nobody had answered you after many hours of your original post. That can be frustrating when you keep checking back several times a day.
I have taken some terrible photos with the G1 due to user errors, focus being just one. I have been able to understand most of my focus problems after reading the dpreview thread and recommend it to everyone as a "must read".
10th of August 2001 (Fri), 14:21
Good summary on focusing threads.
For completeness sake on this topic, here is another reference on G1 focusing:
followed by some G1 Macro Tips I wrote in an old DPReview post:
I would use the minimum number of close up filters and put the UV filter on the outside or remove it if you get any vignetting.
1. If at all possible use a tripod. If not possible, plan on taking lots of shots with a VERY low success rate. When you get really close for these macros you really have to consider the lighting. The internal flash often doesn't work very well at these distances.
2. Use F8 for max. dof (see why you need a tripod, your shutter speed will be very slow?) in Av mode. Wide angle will get you the closest distance but lighting the subject will be more difficult because you will be only 2 1/2 inches away or even closer with close-up filters. Actually maximum zoom will give you a little larger image and much better lighting (since your shadow will not be in the way) but will decrease your dof. How much dof do you want?
3. Set manual focus to minimum distance
4. If in RAW, switch temporarily to JPEG. When in JPEG use digital zoom to 4X by pressing SET and zoom lever at the same time.
5. Using the enlarged image on the LCD move the camera (tripod) for fine adjustments to focus. This is a finer adjustment than using the focus motor in the camera. One can even buy tripod arms with a threaded adjuster for macros.
6. Reverse all actions in step 4 to 1X digital zoom (and RAW if used) and take pic. It you are willing to sacrifice some in image resolution, experiment by taking the pic in 2x digital zoom at max telephoto. It will look better on the computer than on the LCD.
Alternate method: the F8 trick
If you really want to use the internal flash and/or don't have a tripod, you can use the F8 trick in which the G1 is flash synch to 1/250 sec which is fast enough for many action shots.
1. In Tv mode set shutter to 1/640 or faster and turn on flash.
2. zoom out in telephoto to get further away from your subject, otherwise the lens/lens adapters will cast a shadow on your macro subject. Also the flash will be less harsh at longer distances.
3. press macro focus button, focus and take shot as normal.
4. upon immediate image review you may need to decrease the flash intensity with the flash compensation control and try again.
5. If you have a tripod you can do the digital zoom/ manual focus method as above instead of auto macro focus.
Good luck, macros are a lot of fun!
Regards, Mike K
10th of August 2001 (Fri), 14:33
- The focusing zone narrows to roughly the size of the spot metering box if you select spot metering
I've been experimenting with my G1 for the last few days and have concluded that the focusing zone is the same whether the spot metering rectangle is on or off. Having it on (displayed), may assist you in centering the focusing zone.
I also think that the focusing zone is centered but is 2 to 3 times the length & width of the spot metering rectangle. (4 to 9 times the area).
I agree with all of your other statements.
I have only owned a G1 and a Canon S10. I really can't say how the G1 compares to the competition. Focusing will be something I thoroughly research before my next digicam.
10th of August 2001 (Fri), 14:56
This was the conclusion of someone who used a moving Q-tip shaped piece of paper to measure the focus zone. I haven't tried this myself. Everyone else seems to find, as you do, that the zone is smaller than the whole field of view but larger than the spot zone. Don't know who to believe until I try determining it myself.
10th of August 2001 (Fri), 20:00
NOW you may be on the right track. "Try it for myself".
When I learned to shoot a gun, I always wondered, "Do I cover the target with the front sight?; Do I hide the target with the front sight?; Do I split the difference?".
My Dad said it doesn't matter, just do it the same way every time for each gun you shoot and it will be right for you.
Since all G1's are not created equal, according to many posts, we may all need "sight" our G1 focus mechanisms for optimum performance. I don't care where Bob William's G1 focuses as long as my rose, by any other name, is as sweet.
The dpreview thread gives several sighting tips that I can't wait to try.
11th of August 2001 (Sat), 18:21
I just picked up an ultra-low-tech object (too simple to call it a gadget) to help me tell when the G1 photos I'm about to take are in focus.
It's called Magnabrite, cost me $21, and should be available at a photo store near you. Or, you can get it from the company here:
It's a lucite cylinder about two and a half inches in diameter and two inches high. The upper half is sculpted into a convex shape so that it magnifies by 4x whatever is lying under it. I place it on the LCD screen of the G1 and it sufficiently magnifies the image so it's apparent what's in focus and what's not. Much clearer and easier to use than digitally zooming in and then zooming back.
12th of August 2001 (Sun), 07:09
> I just picked up an ultra-low-tech object (too simple to call it a gadget) to help
> me tell when the G1 photos I'm about to take are in focus.
> It's called Magnabrite, cost me $21, and should be available at a photo store near
> you. Or, you can get it from the company here:
> It's a lucite cylinder about two and a half inches in diameter and two inches
> high. The upper half is sculpted into a convex shape so that it magnifies by 4x
> whatever is lying under it. I place it on the LCD screen of the G1 and it
> sufficiently magnifies the image so it's apparent what's in focus and what's not.
> Much clearer and easier to use than digitally zooming in and then zooming back.
But I thought the point of using the digital zoom was to get more information on the LCD to make a determination of what the focus was. This was why this trick doesn't work in RAW mode, because there isn't more information to get. Wouldn't the magnabrite suffer the same limitations?
Having said that, I think it still would be useful, for alas, my eyes doen't seem to be able to see what is in focus whether I use digital zoom or not.
12th of August 2001 (Sun), 11:03
Of course the Magnabrite can't add information, but it does make the LCD easier to see, just like the magnifying eyepiece of an SLR magnifies the ground glass the through-the-lens image is projected onto. I dimly recall that on one old Pentax I had, you could remove the prism and look right at the ground glass. It was just as hard to focus that way as it is, now, to look at the tiny LCD.
One problem with the digital zoom, which effectively also just magnifies the image, is that you then see only a fraction of the frame you are shooting. With the Magnabrite, you can see the whole frame and for me, anyway, it's easier to get a sense of what the final image is likely to look like, even though the individual pixels of the LCD are now larger.
13th of August 2001 (Mon), 18:56
Thanks for the excellent tips. I have a rare coin collection (rare for me is coins nobody know's what the hell they are, me included) that I want to shoot and turn into screen savers. I plan to use direct sunlight against a flat rock or something so light will be a minimal factor. Your tips on getting the best focus will help a lot. I have the 1-2-3 macro set I ordered with my lensmate if I need super-magno bad mamma git down focus.
Also, I plan to use Photoshop to merge front and back shots into one image. It will be fun and can't wait for another day off to give it a try!
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